Improving water quantity

Issue

Many rivers and lakes in Waitaha/Canterbury have reduced flows, levels, or modified natural characteristics due to human activities.

Causes

This can be caused by unsustainable water removal, damming, and diverting of surface water and groundwater. Climate change hazards also impact on freshwater flows and levels.

Why it matters

Freshwater ecosystems and the natural character of rivers, lakes, streams, wetlands and aquifers are dependent on sufficient surface water flows and groundwater levels. Unsustainable removal of freshwater impacts natural flow and level characteristics which compromise the health of the ecosystems they support. Removing too much water can also increase the frequency and duration of dry river reaches, particularly when combined with the impact of climate change on natural flows. Reduced flows can impact the ability of rivers and lakes to dilute contaminants, leading to higher instream contaminant concentrations. Some land-use activities that rely on freshwater may also have an impact on greenhouse gas emissions.

The levels and flows of rivers, lakes, streams, wetlands and aquifers affects their mauri, which is of utmost importance to mana whenua. The relationship between mana whenua and freshwater forms a fundamental part of cultural identity, and degraded mauri negatively effects this relationship.

Our current goals

The current goal is to manage freshwater quantity in an integrated and sustainable way that protects intrinsic values of rivers, lakes, streams, wetlands and aquifers while maximising the ability of freshwater to increase economic productivity and the area of land irrigated in the region.

The current method of achieving this goal is to set minimum flow and allocation limits that protect base flows, flow variability and water levels, while also providing reliability of supply for customary use, community needs and economic purposes. High-flow harvesting and water storage are supported in limit setting, while requirements to use water more efficiently allows allocated water to support further development. Where allocation limits are exceeded, overallocation must be phased out over time.